1. Technical Field
An improved liquid formulation is disclosed which effectively removes odors embedded in soft surfaces such as carpeting and upholstery. The improved formulation makes use of triethylene glycol and a combination of nonionic and ionic surfactants, one of which has bactericidal properties.
2. Description of the Related Art
It has been known to use certain glycols in aerosols or vapor forms to sanitize air in a room by killing airborne bacteria. One particular glycol, triethylene glycol (“TEG”), has been found particularly effective for sanitizing air when delivered via an aerosol spray. The commercially successful OUST® air sanitizer products utilize a mixture that contains about 6 wt % TEG. A non-aerosol application of TEG for disinfecting air is enclosed in U.S. Pat. No. 5,591,395, commonly assigned with the present application. TEG has also been used as an air treatment for tobacco smoke. See U.S. Pat. No. 6,395,236.
Triethylene glycol has the following structure:
TEG is a colorless, odorless, non-volatile and hygroscopic liquid. It is characterized by two hydroxyl groups along with two ether linkages which contribute to its high water solubility, hygroscopicity and its ability to neutralize airborne odor-causing bacteria. TEG can be prepared commercially by the oxidation of ethylene at high temperatures in the presence of a silver oxide catalyst, following by hydration of the ethylene oxide to yield mono-, di-, tri- and tetra-ethylene glycol products. TEG has a low toxicity.
Until now, the treatment and removal of odor-causing substances from soft surfaces such as clothing, drapes, bedding, carpeting and upholstery utilize very different mechanisms. One strategy uses water-soluble cyclodextrins for odor control as discussed extensively in U.S. Pat. Nos. 5,760,475, 6,077,318, 6,248,135 and 6,451,065. These patents all teach the use of water-soluble cyclodextrins in combination with water-soluble metallic salts.
Cyclodextrins have a toroidal structure, the interior of which is hydrophobic. The exterior of this toroid structure is hydrophilic thereby rendering them water-soluble. It has been found that hydrophobic odor-causing compounds enter the hydrophobic interior of a cyclodextrin toroid and form a stable complex with the cyclodextrin structure due to the interplay of Van der Waals forces, the effects of hydrogen bonding and the common hydrophobicity of the cyclodextrin interior and odor-causing molecule. By forming stable complexes with odor-causing molecules, cyclodextrins keep the molecules out of the air thereby reducing the odor caused thereby. Water-soluble metallic salts may be combined with the cyclodextrins to absorb amines and sulfur-containing compounds.
A second approach utilizes water soluble/dispersible polymers as taught in U.S. Pat. No. 6,454,876. In contrast to cyclodextrins, which entrap or cage the odor-causing molecule within the cyclodextrin toroid as discussed above, the water soluble/dispersible polymer of the '876 patent entraps the odor-causing molecule by forming a film that blankets the odor-causing molecule. The film is formed as the solvent or carrier evaporates. Thus, the residual polymer film provides a barrier to contain the odor-causing material in the soft surface thereby preventing it release to the ambient environment and detection by the consumer's sense of smell.
Both the cyclodextrin and film-forming polymer products leave a residue after the solvent or carrier evaporates. Further, neither cyclodextrins nor film-forming polymers have any anti-microbial properties.
Other more drastic measures at treating odor-causing molecules trapped in carpeting, upholstery and clothing involve the use of enzymes or detergents to remove the odor-causing molecules. In the case of upholstery and carpeting, professional services or the renting of special machinery is often required.
Therefore, there is a need for an improved means for removing odors in soft surfaces that are not easily washable, i.e., carpeting and upholstery. What is needed is an improved liquid application that may be sprayed onto carpeting or upholstery, that will not discolor or form a film or residue on the carpeting or upholstery, and that will effectively deliver active odor-neutralizing ingredients to odor-causing molecules trapped in the carpeting or upholstery.